Patent Literature 1 discloses an ejector and an ejector-type refrigeration cycle. The ejector has a refrigerant suction port that draws a refrigerant as a suction refrigerant by using suction force of an injection refrigerant injected at a high speed. The ejector mixes the injection refrigerant and the suction refrigerant to be a mixed refrigerant and increases a pressure of the mixed refrigerant. The ejector-type refrigeration cycle is a vapor compression refrigeration cycle device having the ejector as a refrigerant pressure reducer.
The ejector of the Patent Literature 1 has a body that houses a passage defining member having a truncated cone shape. A refrigerant passage is defined between the body and a side surface of the passage defining member. The refrigerant passage has an annular shape in a cross section. The refrigerant passage has a most-upstream portion and a most-downstream portion in a refrigerant flow direction. The most-upstream portion serves as a nozzle passage that reduces a pressure of a high-pressure refrigerant and then injects the decompressed refrigerant. The most-downstream portion serves as a diffuser passage. The diffuser passage mixes the injection refrigerant and the suction refrigerant and increases the pressure of the mixed refrigerant.
The body of the ejector disclosed in Patent Literature 1 has a swirl space therein. The swirl space is a swirl flow generator that causes a swirl flow in the refrigerant flowing into the nozzle passage. Specifically, a subcooled liquid-phase refrigerant swirls in the swirl space such that a refrigerant around a swirl center is decompression-boiled. As a result, a gas-liquid two phase refrigerant, in which a gas-phase refrigerant is concentrated around the swirl center, flows into the nozzle passage.
Thus, it is an objective of Patent Literature 1 to promote the refrigerant to boil in the nozzle passage and thereby improving energy conversion efficiency when converting pressure energy of the refrigerant into kinetic energy in the nozzle passage.